JPS61280016A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize the long-time recording of a magnetic recording medium by forming recording tracks while decreasing movement distance so that an azimuth angle is larger and larger as a magnetic head is closer and closer to the outer periphery of the recording medium when a signal is recorded and reproduced. CONSTITUTION:When a signal is recorded, an arm 3 is rotated by a stepping motor 6 intermittently at a constant speed or constant period and the magnetic head 4 form a spiral recording track or concentric tracks on a magnetic disk 1. In this case, the azimuth angle when an innermost peripheral track 1 is formed by the magnetic head 4 increases nearly from 0 deg. as the head moves to the outer peripheral circumference by the rotation of the arm 3. Namely, the angle increases in the extension direction of the gap of the magnetic head 4 and a track normal direction and the recording width of the gap decreases, and the width of recording tracks decreases toward the outer periphery. Consequently, the recording area per one track is uniform from the inner periphery to the outer periphery and the track pitch is narrower at the outer peripheral part than at the inner peripheral part, increasing the recording density of the outer peripheral part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a magnetic recording and reproducing apparatus that records and reproduces signals concentrically or spirally on a disk-shaped magnetic recording medium.

(Prior art) A method for recording and reproducing signals on a disc-shaped magnetic recording medium (hereinafter referred to as magnetic disk, etc.) such as a magnetic disk is to rotate the magnetic disk at a constant speed, and move the magnetic head to the radius of the magnetic disk. A method of recording and reproducing signals while moving in the direction, so-called CAM (Constant Angu
A signal recording and reproducing method using a lar velocity (lar velocity) method is known.

In this method, a magnetic head is generally operated to move in the radial direction of a magnetic disk, etc. at a constant period or at a constant speed, thereby forming concentric or spiral recording tracks with a constant pitch on the magnetic disk, etc. be done. The recording signal is sent to the C11 head at a constant speed. Therefore, since the recording density is highest at the innermost circumference of a magnetic disk, the signal recording speed is set at a predetermined speed at this innermost circumference. The settings are made so as to ensure an S/N ratio of .

However, it is usually sufficient to ensure the same S/N ratio on the outer periphery as on the inner periphery;
Rather than increasing the N ratio, it is more rational to increase the recording density at the outer circumference to the same level as that at the inner circumference to enable long-term recording. Especially in today's world where the density of information is rapidly increasing, it is urgent to achieve long-term recording on recording media, and in particular, the CAV method mentioned above has a simple servo circuit and can easily perform operations such as random access. It has become a social demand to achieve long-term recording using methods using .

(Purpose of the Invention) The present invention has been made in view of the above circumstances, and is intended to provide a magnetic recording/reproducing device using the CAV method, in which the recording density of the outer circumferential portion of the magnetic recording medium is equal to or higher than the recording density of the inner circumferential portion. It is an object of the present invention to provide a magnetic recording/reproducing device that can achieve long-time recording on a magnetic recording medium by increasing the size to a similar extent.

(Structure of the Invention) The magnetic recording/reproducing device of the present invention is characterized in that when the magnetic head is moved in the radial direction of a disc-shaped magnetic recording medium to record and reproduce signals, the magnetic head is located at the outer periphery of the recording medium. The recording track is formed by changing the azimuth angle of the magnetic head so that it becomes larger and the moving distance of the magnetic head becomes smaller.

Further, in the magnetic recording/reproducing apparatus of the present invention, a magnetic head brought into contact with a disc-shaped magnetic recording medium rotated by a spindle is moved in the radial direction of the recording medium by means of a carriage means, and an azimuth angle of the magnetic head is moved by a carriage means. The recording track is formed by changing the azimuth angle so that the azimuth angle becomes larger and the track pitch becomes smaller as the magnetic head is located on the outer periphery.

Further, the magnetic recording medium used is characterized in that the width and pitch of recording tracks are formed smaller toward the outer circumference.

Note that the degree to which the azimuth angle is changed and the width of the recording track must satisfy the condition that the recording density of any recording track does not exceed the recording density of the innermost recording track.

Here, recording density is recording track width x recording track 1
It is the reciprocal of the circumference length.

(Effects of the Invention) According to the magnetic recording and reproducing method of the present invention, the azimuth angle of the magnetic head increases as the magnetic head is located at the outer periphery of the disk-shaped magnetic recording medium, and the width of the recording track decreases as the outer periphery increases. In addition, since the track pitch at the outer circumference is narrower than that at the inner circumference, it is possible to increase the recording density at the outer circumference compared to the method conventionally used in the CAM system. This allows for efficient use of recording media.

Therefore, the servo @ CL (Constant 1-inear V) is complicated and difficult to access randomly.
It is possible to achieve long-term recording without using methods such as the ``elasticity'' method.

According to the magnetic recording/reproducing apparatus of the present invention, the azimuth angle changing means is used to adjust the azimuth angle of the magnetic head relative to the recording track so that the closer the magnetic head is to the outer periphery of the disk-shaped magnetic recording medium, the larger the azimuth angle of the magnetic head becomes. The width of the recording track is made smaller toward the outer circumference by changing the inclination. Furthermore, since the track pitch on the outer circumference is made smaller than the track pitch on the inner circumference, the recording medium can be recorded at a higher density on the outer circumference than in devices conventionally used in the CAV system. Therefore, long-term recording can be achieved without using methods such as the CLV method.

According to the magnetic recording device of the present invention, the width of the recording track becomes smaller toward the outer circumference, and the track pitch at the outer circumference is formed smaller than the track pitch at the inner circumference. Compared to magnetic recording media recorded using the conventional CAV method, high-density recording can be achieved at the outer periphery, and the recording time can be extended for a long time.

(Embodiments) Hereinafter, embodiments of the present invention will be described using the drawings.

FIG. 2 is a schematic diagram showing a part of the magnetic recording/reproducing apparatus of the present invention.

As shown in FIG. 2, a magnetic disk 1 is rotatably held on a spindle 2 and is brought into contact with a recording/reproducing magnetic head 4 attached to the tip of an arm 3. As shown in FIG. One end of the arm 3 is attached to a mounting part 6 of an arm mounting member 5, and a stepping motor (not shown) for rotating the arm 3 at a predetermined angle is housed in the mounting part 6. ing. Further, in this device, a recording signal from a recording amplifier (not shown) is input to the magnetic head 4, and a reproduction signal read by the magnetic head 4 is input to the reproduction amplifier (not shown). ) is output.

FIG. 1 is a schematic view of the apparatus of FIG. 2 from above.

The arm 3 rotates around a mounting portion 6 disposed on a tangent to the innermost track 1 as a rotation center. The rotation angle range is from an angle at which the magnetic head 4 attached to the tip of the arm 3 can form the innermost track 1 to an angle at which the outermost track O can be formed.

In the magnetic disk 1 shown in FIG. 1, the recording tracks are formed such that the radius A of the innermost track is 34.40 All, and the radius A of the outermost track is 57.60 #Il. Note that the length C of the arm is set to 23#W.

By the way, when recording a signal, the arm 3 is intermittently rotated at a constant speed or at a constant cycle by a stepping motor within the above-mentioned range, so that the magnetic head 4 is
forms spiral or concentric recording tracks on the magnetic disk 1. In this case, when the magnetic head 4 forms the innermost track 1, the azimuth angle is approximately O.
The azimuth angle increases as the arm rotates and the magnetic head 4 moves toward the outer periphery.

That is, as the magnetic head 4 moves toward the outer periphery, the angle formed between the direction in which the gap of the magnetic head 4 extends and the track normal direction becomes wider (as a result, the substantial recording width due to this gap becomes smaller).

As a result, the width of the recording track is formed to become smaller toward the outer periphery, as shown in FIG. 3 (the width is exaggerated compared to the actual width). More specifically, the stepping motor is controlled so that the width and pitch of the recording track are inversely proportional to the distance from the position to the center of the magnetic disk 1.

In the recording track of the magnetic disk 1 formed in this way, the recording area per track round (track width x length of one track round) is approximately uniform from the inner circumference to the outer circumference,
Since the track pitch at the outer circumference is narrower than the track pitch at the inner circumference, the recording density at the outer circumference can be increased. According to experimental results obtained by the present inventors, it was possible to increase the recording time of the magnetic disk 1 by about 20% compared to the conventional CAV method.

Regarding the electromagnetic conversion characteristics when recording on the outermost track, substantially the same results as when recording on the innermost track were obtained.

Furthermore, when reproducing signals from the magnetic disk 1 on which signals have been recorded in this manner, the arm may be rotated to read the signals of each recording track in the same manner as in the case of signal recording.

In the above embodiment, specific values are shown for the radii A and B of the innermost track and the outermost track, and the arm length C, but of course they are not limited to these values and may be changed depending on the purpose. Further, an appropriate value may be selected while taking into account frequency characteristics and the like.

Note that the track width or track pitch is not limited to the values explained in the above embodiments, and if the value on the outer circumference is set to be smaller than the value on the inner circumference, the value may be increased or There is no harm in reducing it.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing embodiments of the present invention,
FIG. 3 is a schematic diagram showing an embodiment of a magnetic disk used in the magnetic recording/reproducing apparatus of the present invention together with formed recording tracks.

Claims (3)

[Claims] (1) A spindle that rotates a disk-shaped magnetic recording medium, a magnetic head that comes into contact with the magnetic recording medium to record and reproduce signals on the magnetic recording medium, and a magnetic head that is attached to the outer periphery of the magnetic recording medium. a carriage means for moving the magnetic head substantially in the radial direction of the magnetic recording medium at a certain speed so as to form a concentric or spiral trajectory of the magnetic head on the magnetic recording medium; A magnetic recording and reproducing device comprising azimuth angle changing means for changing the inclination of the magnetic head with respect to the trajectory so that the azimuth angle of the magnetic head increases as the distance from the center of the recording medium increases. Device. (2) The carriage means has one end disposed near a tangent to the innermost trajectory of the concentric or spiral trajectory, and has the magnetic head attached to the other end, and rotates the one end. 2. The magnetic recording/reproducing device according to claim 1, wherein the magnetic recording/reproducing device is an arm that rotates over a predetermined angle about the center. (3) The rotation of the arm is controlled by a stepping motor, and the control operation related to this rotation is such that the width and pitch of the locus formed by the magnetic head is adjusted from the magnetic head to the center of the magnetic recording medium. 3. The magnetic recording/reproducing apparatus according to claim 2, wherein the magnetic recording/reproducing apparatus is set to have a value inversely proportional to the distance to the magnetic recording/reproducing apparatus.